Is a 15-Year $400,000 Mortgage Worth the Higher Payment?

When considering a $400,000 mortgage, the choice between a 30-year and a 15-year loan isn’t just about monthly affordability—it’s about how much interest you’ll pay over time and how your payments evolve with interest rate fluctuations. The table below shows the monthly payment and total lifetime interest for a $400,000 mortgage, comparing a 30-year and a 15-year term across a range of APRs. These figures reveal how drastically different financial outcomes can be, even within the same loan amount and rate environment.

Monthly Payments: The Trade-Off Between Flexibility and Cost

A 30-year mortgage typically results in a lower monthly payment than a 15-year loan, making it more accessible for borrowers with tighter budgets. For example, at a 5% APR, a 30-year loan might produce a monthly payment of around $2,374, while a 15-year loan could be nearly $3,300—almost 40% higher. However, this higher monthly burden comes with a significant cost: over 30 years, the total interest paid on a 30-year loan at 5% could exceed $200,000. In contrast, a 15-year loan at the same rate would pay less than $100,000 in interest over its term. This means that while the 30-year option offers more flexibility, it results in nearly double the interest paid over the life of the loan—especially at higher APRs.

Lifetime Interest Costs: How Rates and Terms Multiply Over Time

The table shows that even small differences in APRs compound over decades. For instance, a 30-year mortgage at 6% APR could result in over $250,000 in total interest, whereas a 15-year loan at the same rate would pay less than $130,000. At 7%, the interest gap widens: a 30-year loan would pay over $300,000 in interest, while a 15-year loan would pay under $180,000. These figures highlight a critical point: borrowers who plan to stay in a home for 30 years may end up paying significantly more interest with a 30-year loan—especially if rates rise. Conversely, those who expect to sell or refinance within 10–15 years may benefit from the shorter term, even with higher monthly payments.

When the 15-Year Loan Makes Financial Sense

A 15-year mortgage is most advantageous for borrowers with stable incomes, strong credit, and a clear exit plan within a decade. It reduces total interest paid by nearly 50% compared to a 30-year loan at the same rate, which translates into hundreds of thousands of dollars saved over time. This is particularly valuable when interest rates are low or expected to rise. For example, if a borrower is confident they will sell their home within 15 years, the shorter term offers a faster path to full repayment and lower lifetime interest. However, the higher monthly payments may strain cash flow, especially if the borrower has other financial obligations.

How We Calculated This

The numbers in the table were derived using standard amortization formulas applied to a $400,000 loan, with monthly payments calculated based on a fixed APR and a constant compounding interest rate. The total interest paid over the life of the loan was computed by summing all monthly payments minus the principal repaid. The APR range used reflects current market conditions, and the results are consistent with U.S. mortgage benchmarks. The table does not include taxes, insurance, or points, and is based solely on principal and interest. These figures are designed to illustrate the long-term financial trade-offs, not to provide personalized financial advice.

$400,000 mortgage — monthly payment and lifetime interest, 30-year vs 15-year, by rate

Rate	30-yr Payment	30-yr Interest	15-yr Payment	15-yr Interest
6.0%	$2,398	$463,353	$3,375	$207,577
6.5%	$2,528	$510,178	$3,484	$227,197
7.0%	$2,661	$558,036	$3,595	$247,156
7.5%	$2,797	$606,869	$3,708	$267,449